In natural language processing (NLP), input text data can be processed to obtain a list of parse items that may or may not represent known terms and phrases. Some parse items are associated with modifiers or attributes that tend to describe certainty or temporality of a word being modified. In medical coding, parse items tend to represent medical conditions with the attributes providing appropriate modifications. Such parse items can be compared against known vectors that represent descriptions of diagnoses and medical procedures to assign appropriate medical codes to the input text data (e.g., physician notes.)